Method of making heat insulating tape



Feb. 27, 1934. G. s. FABEL METHOD OF MAKING HEAT INSULATING TAPE 2 Sheets-Sheet 1 Filed Dec. 17, 1932 Feb. 27, 1934. G; a FABEL 1,949,298

METHOD OF MAKING HEAT INSULATING TAPE Filed Dec. 17, 1932 2 Sheets-{Sheet 2 Z nve 0/7 tilt Patented Feb. 27, 1934 UNITED STATES PATENT OFFICE George S. Fabel,

Trenton, N. 3., assignor to Southern Asbestos Company, Charlotte, N. 0., a corporation oi Delaware Application December 1?, 1932 Serial No. 5471397! ,8 @laims.

This invention relates to a heat insulation tape comprising an asbestos-filled asbestos textile tube and method oi producing the same, and more particularly to a method of inserting an integral and continuous asbestos roving in an asbestos textile tube where the roving is of such character that it cannot be drawn into the tube against the friction of the roving on the-walls of the tube without P rting.

a further and more specific object of the invention is the production of a textile tube formed irom asbestos and'containing an asbestos roving which is either entirely without twist, or with a very slight twist so that the fibres thereof are not compacted and solidly felted and the roving is free to expand against the walls of, and completely fill, the tube; and in which no binding about the roving is resorted to.

Asbestos iabric tubes containing asbestos rovings of various types have been employed for some time as a means for heat-insulating pipes. As is well known to those familiar with the art, tightly packed asbestos is not an eficient heat insulation, it being necessary to emciency that the roving or nllirm oi the tube be as flufiy and soft as is possible. Asbestos fibres have no real tensile strength and, quite obviously, in order to produce a filled tube the roving must either be twisted to such an extent that a great deal of efliciency is destroyed, or bound with surrounding cords which have a tendency to pack the material of the rev:- ing and prevent it from properly filling the tube, in event the tube employed is in the form of a tube at the time the filling is disposed therein. This has led to the manufacture of insulating tapes of this character by laying the roving loosely on a piece oi fabric and seaming the'edges oi the fabric about the roving. This is not satisfactory, because it causes a pinch at one side of the tube with a corresponding loss of efilciency at such side and an unnecessary width of the completed prod not. 1

a second method is to'paste the edges of the tube, but this method is unsatisfactory in that the tube isincapable of use for more than one application, the pasted joint failing due to the hansing and the heat to which it is subjected. A

l have discovered that it is possible to insert sush rovings in a completed textile tube by employing the frictional engagement of the roving with the walls oi the tube 'tohold the roving against movement with relation to the walls of the tube while withdrawing the roving from a.

supporting surface upon which it is disposed, and

which has such characteristics that the roving tube, said roving,

tucked into the tube to a suitable traction may slide thereover with exercise of that slight longitudinal strain thereon which the roving is capable of withstanding.

This method may be conveniently carried out by apparatus such as that illustrated in the acw companying drawings wherein, for the purpose of illustration, 1 have shown several forms of ap paratus for this purpose.

In the drawings:

Fig. 1 is a perspective view of a fragment of an it insulating tape constructed in accordance with my invention;

Fig. 2 is a longitudinal sectional view, diagram= matic in nature, illustrating one method of insert ing the roving in the tubing;

Fig. 3 is a similar view showing a second method of inserting the roving;

Fig. i is a sectional view showing the initial step of a third method;

Fig. 5 shows the method;

Fig. 6 shows the final step of the third method;

Fig. 7 is a sectional view through the roving= inserting apparatus employed in the third method; and so Fig. 8 is an enlarged sectional view through the forward end of the inserting tool employed in the third method.

Referring now to the drawings, and more par ticularly to Fig. 1 thereof, the numeral 10 designates a textile tube. formed from asbestos strands, and 11 an asbestos roving filling said as indicated by the legend, being non-twisted, laterally unconfined, and longitudinally unitary. The roving 11 is, furthermore, characterized by the facts that it fills the tube, and that it is of insuficient tensile strength to admit of its being drawn through a tube of the length in which it is disposed.

This roving may be placed in the tube by any of the following methods, reference being first had to the method illustrated diagrammatically in Fig. 2. By this method, the roving 11 is placed upon a smooth; and preferably polished, support 12, said support preferably inclining downwardly toward one end thereof. At the lower end oi the support, a metal tube 13 is disposed,'this tube being of suiiicient length and diameter to admit of, a desired length of the textile tubing 10 being slipped thereover, as indicated. The end of the tubing 10, which is at that end of the tube 13 adjacent support 12, is

13 and has attached thereelement 14, such as a heavy intermediate step of the third 36 not cord. {The end or the roving 11 is introduce! the tucked-in end 01' the textile tube, as at 15. The friction of the tucked-in end upon the textile tube will be sufiiclent to draw roving 1i downwardly upon support 12 and the textile tub ing 10 as it passes around the end of the tube 13 simply rolls upon the face of the roving so that there is no drag exerted upon the roving at any time except such drag as is necessary to cause the same to slide upon the smoothed and polished support 12, a portion of this drag being eliminated by the gravitational efiects obtained through inclination of the support. The roving may thus be introduced to the tubing Without breakage, or without any packing efiect thereon.

Fig. 3 illustrates a similar method, in which a metal tube 16 is employed having at one end an introducing mouth 17. The roving 11 is introduced through this tube while the tubing 10 is threaded upon the exterior of the tube. Both the end of the roving and the end of the tubing are permitted to extend slightly beyond the end of metal tube 16 so that they may be simultaneously grasped, as at 18. It will be obvious that if the tubing 10 is now pulled longitudinally from the tube 16, the roving 11 win simply slide through the tube 16 and the only friction against the roving will be the friction of the tube which is, of course, interiorly polished so that such friction is reduced to a minimum. As in the case of the support 12, tube 16 is preferably given an inclination so that the forces of gravity act to assist in moving the roving therethrough.

By the method employed in Figs. 4 to 8, a tubular inserting tool 19 is employed. This inserting tool comprises two trough-shaped elements 20 and 21, the element 20 having a tapered nose 22 to which a cap piece 23 is pivoted, preferably by means of a ring 24 through which a traction element such as a stout cord 25 may be attached to the inserting tool. The cap 23 fits over the nose end of the section 21 so that this section is prevented from catching in the fabric of tool is drawn in Fig. 5, and then the opposite ends of sections 20 and 21 are engaged and simultaneously moved from the tube in opposite directions. Upon initial separation of the section 21 from cap piece 23, the roving comes into contact with the wall of the tube so that the roving is frictionally held against readily produced. It

ace-ages movement as the sections 20 and 21 are with-= drawn. Furthermore, since withdrawal is in on posite directions, the tendency of the roving to move in either direction is offset and it remains within the tubing 10. The trough sections 20 and 21 are interiorly smooth, and preferably polished so that there cannot be sumcient friction to cause any rupture of the roving. While the use of a seamless tube is preferred, it will, of course, be understood that any preformed tube can be employed, a flat seam being preierred where one is necessary.

It will be obvious that by any or the foregoing methods the insulating tape of Fig. 1 may be will also be obvious that the apparatus employed is capable of consider able modification and I do not wish to be understood as limiting myself thereto except as hereinafter claimed.

I claim:

1. The method of producing insulation tape comprising providing an asbestos textile tube and a roving of unconfined and loosely compacted asbestos fibre, moving the textile tube over and from the end of a shield having a relatively'low coemcient of friction as compared to the textile tube, passing the roving through said shield and employing the frictional engageof the roving with the tube to draw the roving through the shield.

2. The method of producing insulation tape comprising providing a preformed asbestos textile tube and a roving of unconfined and loosely compacted asbestos fibre, moving the textile tube over and from the end of a shield having a relatively low coemcient of friction as compared to the textile tube and passing the roving through said shield while employing the frictional engagement of the roving with the textile tube to draw the roving through the shield and maintaining the shield at an angle such that the force of gravity acts to assist the movement of the roving therethrough.

3. Inc method comprising providing an asbestos textile tube and a roving of unconfined and loosely compacted asbestosflbre, moving the textile tube over and from the end of a metallic tubular shield, passing the roving through said shield and causing the same to frictionally engage in the pro- J'ected end'of the textile tube and then employing the frictional engagement of the roving with the tube to draw the roving through the shield.

. GEO. 8. FABEL.

of producing insulation'tape 

